GeologyRocks

Think you'll find the reason is that from Cheshire right across the North Sea to Poland is much the same because it was the Zechstien Sea.  We have evaporate minerals - salt and gypsum in Cheshire, and certainly salt in Poland, and although I've never heard of gypsum deposits there I wouldn't mind betting there are some.

One look at Luneburg Heide and being old sea bed sands out a mile.  I suppose that there must have been large islands with the various ranges of high land which tend in a NW/SE direction, and perhaps the Hartz Mountains were an edge to the sea.

But don't forget some of the lakes around Berlin are actually maars which I can't recall the age of.  But if they are pre Zechstien that would account for infilling with silt.

Further west much of the land, even south of Luneburg, is sandy/silty.  I was never sure about Stienhudermere - certainly sandy/silty and almost perfectly round.  Is it a maar?  I just don't know.  There are some more maars down near the Belgium border.

I don't think you can compare Scotland with northern Germany.  Very different geological history I think you'll find.

    John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

Thanks John. I must read the geological background of both Scotland and Germany then! As I really like lakes with pebbles and stone beds and kind of hate the mystery of sand everywhere (thats why I compared Scotland and Germany,t he only two countries I ever got to swim in their lakes), this gets to be fascinating and I will be checking Norwegian lakes, English lakes, too.

By theory, which countries or areas of |Europe you think must have lakes such as those in Scotland? With rocks and no sand at all?

I think the origin of the lochs/lakes needs to be taken into account too: Scottish lochs were formed at the end of the last Ice Age. I wonder if this is the main cause for the different sediment infill.

Were the Scottish lochs purely the result of the Ice Ages, or perhaps partly to do with the orogenies/thrusts?

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

I'm clueless but if English lakes have silt/mud like German ones, the first theory in this thread is the propable answer. 

 Scottish/Norwegian lakes feel a lot like sea. They have pebbles that become large stones towards the middle. Or they have large stones everwyhere like the shores of Greece, Italy, and most islands in the world.

That question was actually for Jon.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

As far as I know, Scottish lochs are all due to glaciers; they did exploit orogenic weaknesses, such as Loch Ness.

I suspect the difference is a combination of factors:
- origin
- local bedrock
- river input (e.g. sediment load)
- local land use

I doubt it can be entirely be one cause. However, if there is sediment in the bottom of a lake it must have been transported in there by river, surface run off, or sediment dropping onto the surface and sinking.

Almost certain to be river silt in there, and probably quite a bit of peat.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant